2N6491 PNP Bipolar Transistor Equivalent & Substitute Parts

Part Overview

The 2N6491 is an obsolete PNP bipolar junction transistor manufactured by onsemi, rated for 80 V collector-emitter breakdown voltage and 15 A maximum collector current in a TO-220-3 through-hole package. The device is designed for general-purpose switching and amplification applications requiring moderate power dissipation of 1.8 W maximum.

Due to the obsolete product status of the 2N6491, locating original stock from primary distributors presents supply chain challenges. Active production alternatives with equivalent or superior electrical characteristics are available to maintain circuit functionality and ensure long-term component availability.

Substiute Parts

2N6491

onsemiIn Stock: 23942N6491 Datasheet

Current PartRFQ

2N6491G

onsemiIn Stock: 102202N6491G Datasheet

DirectRFQ

BD912

NTE Electronics, IncIn Stock: 1965BD912 Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the 2N6491 is determined by the following critical parameters:

Primary Compatibility Criteria:

• Transistor type must be PNP
• Collector-emitter breakdown voltage must equal or exceed 80 V
• Maximum collector current must equal or exceed 15 A
• Package type must be TO-220-3 through-hole configuration
• Operating temperature range must encompass -65°C to 150°C

Substitution Categories:

Direct Equivalent: Parts meeting all primary criteria with identical electrical specifications and active product status.

Functional Equivalent: Parts meeting all primary criteria with enhanced electrical specifications (higher voltage rating, higher power rating, or improved frequency response) that maintain backward compatibility in the 2N6491 application circuit.

Parameter Comparison

Engineering Selection Recommendations

2N6491G (Direct Equivalent - Recommended Primary Choice)

The 2N6491G is the preferred substitute for the obsolete 2N6491. Both devices are manufactured by onsemi and share identical electrical specifications across all critical parameters: 80 V breakdown voltage, 15 A collector current, 1.8 W power rating, and 5 MHz transition frequency. The 2N6491G maintains active product status with significantly higher inventory availability (10,200 units in stock versus 2,344 units for the original 2N6491). The 2N6491G achieves ROHS3 compliance, whereas the 2N6491 is RoHS non-compliant. Pin-for-pin compatibility and identical thermal characteristics ensure direct circuit substitution without design modification.

BD912 (Functional Equivalent - Enhanced Specifications)

The BD912 manufactured by NTE Electronics, Inc qualifies as a functional equivalent with enhanced electrical performance. The BD912 provides a higher collector-emitter breakdown voltage rating of 100 V compared to the 2N6491's 80 V, offering improved voltage margin in applications approaching the 80 V limit. The BD912 delivers substantially higher power dissipation capability at 90 W maximum versus 1.8 W for the 2N6491, enabling thermal performance advantages in power-intensive circuits. The BD912 maintains the same 15 A collector current rating, TO-220-3 package configuration, and -65°C to 150°C operating temperature range.

Trade-offs with the BD912 include a lower transition frequency of 3 MHz compared to the 2N6491's 5 MHz, and a lower DC current gain specification of 40 @ 500mA, 4V versus 20 @ 5A, 4V for the 2N6491. These differences require circuit-level evaluation for applications with stringent frequency response or gain requirements. The BD912 is RoHS non-compliant, matching the original 2N6491 compliance status.

Frequently Asked Questions (FAQ)

Q: Can the 2N6491G be used as a direct replacement for the 2N6491 without circuit modification?

A: Yes. The 2N6491G is a direct equivalent with identical electrical specifications, package configuration, and pin assignment. No circuit design changes are required for substitution.

Q: What are the advantages of selecting the 2N6491G over the original 2N6491?

A: The 2N6491G offers active product status with superior long-term availability, ROHS3 compliance for regulatory alignment, and equivalent electrical performance. The 2N6491 is obsolete with limited remaining inventory.

Q: Is the BD912 suitable for all 2N6491 applications?

A: The BD912 is suitable for applications where the lower transition frequency of 3 MHz and different DC current gain characteristics do not conflict with circuit requirements. The BD912's enhanced voltage rating (100 V) and power rating (90 W) provide performance margins for demanding applications. Circuit-level verification is necessary for frequency-sensitive or gain-dependent designs.

Q: What is the primary difference between the 2N6491G and BD912?

A: The 2N6491G is a direct equivalent with identical specifications to the 2N6491. The BD912 is a functional equivalent with enhanced voltage and power ratings but reduced transition frequency. Selection depends on whether enhanced power handling or higher voltage margin is required for the specific application.

Q: Are all three parts (2N6491, 2N6491G, BD912) available in the same TO-220-3 package?

A: Yes. All three parts use the TO-220-3 through-hole package configuration with identical mechanical dimensions and pin assignments, enabling direct physical substitution on printed circuit boards.

Q: What is the inventory status for each part?

A: The 2N6491 has 2,344 units in stock but is obsolete. The 2N6491G has 10,200 units in stock and is active. The BD912 has 1,862 units in stock and is active. For long-term supply chain stability, the 2N6491G is the recommended choice.

Q: Does the RoHS compliance status affect substitution decisions?

A: RoHS compliance status depends on end-product regulatory requirements. The 2N6491G is ROHS3 compliant, whereas both the 2N6491 and BD912 are RoHS non-compliant. For applications requiring RoHS compliance, the 2N6491G is the only compliant option among the three parts.